 [nondet]pack_property(?Pack, 
?Property)True when Property is a property of an installed Pack. 
This interface is intended for programs that wish to interact with the 
package manager. Defined properties are:
[nondet]pack_property(?Pack, 
?Property)True when Property is a property of an installed Pack. 
This interface is intended for programs that wish to interact with the 
package manager. Defined properties are:
- directory(Directory)
- Directory into which the package is installed
- version(Version)
- Installed version
- title(Title)
- Full title of the package
- author(Author)
- Registered author
- download(URL)
- Official download URL
- readme(File)
- Package READMEfile (if present)
- todo(File)
- Package TODOfile (if present)